SUPER FAST
Mill can transform 1.4lbs of food scraps into dry, shelf-stable grounds in just 2.5 hours.
Test a new way to fight food waste.
Seattle Public Utilities & King County have reached their enrollment goals for this study and are no longer able to accept new applications to participate.
What does participating involve?
Food Waste Study participants receive a Mill device to use at no cost during the study, starting in March/April 2026. Set it up with the Mill app, mail back Food Grounds when full (packaging and pick-ups provided), and complete a survey.
Mill device usage data (such as pounds of food scraps collected) will be shared with the City and County in an aggregated and anonymized fashion for the purposes of the study. The study will run through October 2026.
Seattle Public Utilities & King County have reached their enrollment goals for this study and are no longer able to accept new applications to participate.
Who is eligible?
Seattle Public Utilities & King County have reached their enrollment goals for this study and are no longer able to accept new applications to participate.
How it works
1
Add your scraps. Mill takes almost anything — even bones and avocado pits — and transforms them into nutrient-rich grounds.
2
Mill works overnight. You don't even have to press a button — Mill knows how much you add.
3
Empty your Food Grounds into prepaid boxes and schedule pickups via the Mill app.
Mill tech specs
(2nd gen)
Quietly powerful
At a soft hum of 41 decibels, Mill is similar in sound level to the quietest air purifier.
Dimensions
37.5”
16.6”
16.6”
13.8”
37.5”
Weight
68 lbs (Total)
12.1 lbs (Empty bucket)
Volume
6.5l / 1.7 gal
Cord
8.2 ft (2.5 m) with 3-prong adapter
WiFi
802.11b/g/n (2.4GHz) Wi-Fi
Mobile App
Mobile App (min. OS) iOS 14 or later Android 10 or later
Voltage
120 V-/60Hz/4.5 A
In the box
Mill
Bucket
Charcoal filter
Integrated Power cable
Food Library magnet
Instructions
FAQs
Nothing! Participation is free, as long as you meet the participating requirements in the "Eligibility" section above.
Seattle Public Utilities and King County aim to study different ways to make it easier for residents to collect food scraps and ultimately reduce the amount of food waste sent to landfills. The Food Waste Study will inform whether food scrap devices can help make it easier for people to separate food scraps for composting or other beneficial uses.
Seattle Public Utilities and King County have leased 300 devices on behalf of residents and multifamily complexes that participate in this study, and as part of a larger effort to lower the barriers to food scrap collection. Once the study is completed, Mill will ask if you want to return or purchase the leased device. You will have the opportunity to purchase your Mill device for $175 + sales tax (regularly $999) as a one-time payment or in installments as a thank you for your participation.
Participants’ privacy will be protected, adhering to Mill’s privacy policy. Device usage data shared with the City & County will be aggregated and anonymized, so it will not be linked to individual participants.
Food Grounds are the dried, odorless, and ground food scraps produced by the Mill device after it heats and grinds up your food scraps. The Mill device runs overnight when it senses there is food inside. You can keep adding food scraps every day until the device is full.
For the purposes of this study, you will need to mail back your Food Grounds, which Mill processes into an ingredient for chicken feed at their facility in Mukilteo, WA. Study participants will receive Mill’s mailback service for free.
Once your Mill device is set up, you will use the Mill App to order prepaid boxes (at no cost) to send back your Food Grounds. When the prepaid box is filled, you will schedule a USPS pickup in the Mill App or drop off at a USPS location.
The Mill food scrap device reduces the volume of food scraps by about 80%, transforming them into dry, odorless Food Grounds. On average, a household of four will only need to empty their Mill every three to four weeks. Each Food Ground mailback box can hold the amount of two to three full Mill devices.
Yes, the device lock settings can be customized in the Mill app to meet your needs. You can set the device to be always locked, locked when running, or always unlocked (see our support page for more information).
Once the study is close to completion, Mill will ask participants if they want to return or purchase the leased devices. Participants will have the opportunity to purchase their Mill device for $175 + sales tax (regularly $999) as a one-time payment or in installments as a thank you for your participation. See customer reviews here. After the study, Food Grounds can be added to curbside food/yard waste carts where available – learn more about how to use Food Grounds here.
Mill’s food scrap device is not a composting device. The Food Grounds that come out of the device, which are created in a matter of hours, are still food, minus the water, bulk, odor and ick. The Food Grounds you send back in this study are used to feed chickens. By contrast, composting typically takes weeks or months to break down food and yard waste into compost.